New Member Early Blight

[Tillerman]

My first post is related to disease. Last year, when we expected to be relocated by mid-Summer I bought starts of a couple of hybrids and a couple of heirlooms from a box store. Normally, I grow my own starts.
I had a clear case of early blight, with the plants all dieing from ground up.
I used a copper spray, with no luck. Only a few small fruits.

I will relocate this year (still haven't moved), as I have the room.
Any thoughts on how far away the new patch needs to be?
Any other thoughts/suggestions are welcome.
Thanks

[Milan HP]

How far could parts of the infected plants get? Alternaria survives on those mainly in the ground. I'd say that the best bet could be on the other side of the house. Did you clean the contaminated area off the plant debris properly throughout the whole season? That is the key.
Milan HP


P.S. You might also consider applying calcium cyanamide (CaCN2) to treat the area where the infected plants used to be. It is said to kill some pathogens and pests. It's a good fertilizer too. Two weeks before you sow or plant anything there.

[MrBig46]

Originally Posted by Tillerman

My first post is related to disease. Last year, when we expected to be relocated by mid-Summer I bought starts of a couple of hybrids and a couple of heirlooms from a box store. Normally, I grow my own starts.
I had a clear case of early blight, with the plants all dieing from ground up.
I used a copper spray, with no luck. Only a few small fruits.

I will relocate this year (still haven't moved), as I have the room.
Any thoughts on how far away the new patch needs to be?
Any other thoughts/suggestions are welcome.
Thanks

Perhaps my compatriot and friend Milan HP will not be angry if I correct him a bit. Early blight is a leaf disease that overwinters on plant remains in the ground. If you have removed all the above-ground diseased parts of the plants, then the spores of Alternaria solani survive only in the remnants of the roots directly on the flowerbed where the plants were grown. So it is enough if you do not grow tomatoes in the same place, but it is possible to grow them right next door. Need not to put tomatoes somewhere on the other side of the garden, but the place of cultivation must be changed every year and on original infested flowerbed can be returned in three to four years.
Vladimír

[Milan HP]

I still consider the wind blown debris of infected plants (dry leaves are brittle) that get onto the adjacent patches a potential hazard. Not a very serious one though, but I believe that it is better to be safe than sorry.

Milan HP


P.S. My nickname is Mr Caution.

[MrBig46]

Theoretically, anything is possible. But it is more likely that the spores of early mold will arrive from somewhere else, as they spread through the air for several kilometers. Nowhere is it written that on the other side of the garden or behind the house, tomato plants will not be infested with this mold next year. It is unrealistic to move tomatoes from one side of the garden to the other every year.
Vladimír

[Milan HP]

Sure, I agree with you. Actually, my first idea was to say it didn't matter how far if not in the same patch. But then I changed my mind and decided for more caution. Like with covid.
Milan HP

[PaulF]

Many diseases including blights and wilts are soil borne and are transmitted by direct contact of leaves with soil. Water splashing on bare soil sends dirt onto leaves and the spores are in place. Any stressed plant is then more susceptible than a stronger plant. As tomatoes age over the growing season they weaken from reproduction and disease is more frequent. Certain varieties also are more susceptible than others.

An important safeguard to soil borne diseases like blights and wilts is a good mulching program. A barrier between soil and plant will go far in reducing disease. I use newspaper as a first layer and straw on top of that. After having tried several different combinations, for me this has reduced disease tremendously. My garden is so small it is impossible to rotate the crops enough that there is no overlap. I credit mulch with successful reduction in pathogen transmission...not elimination, but great reduction.

[MrBig46]

I also use mulching - black woven fabric. In the spring, the black foil does not look very nice, but when the tomatoes grow, it is not visible at all. I water with a hose with holes placed under the foil

[b54red]

I grow so many tomatoes each year that it is almost impossible to plant where diseased plants were not the year before in my small garden. I mulch heavily and before planting spray the mulch with a 10% solution of bleach and water making sure to wet all the exposed mulch. Next I spray with Daconil regularly for at least the first two months when EB is so likely to pop up. I will switch to a copper spray if I am having difficulty with any type of gray mold, spot or speck diseases. I also usually spray my whole tomato bed with a more diluted bleach spray every month or so. I have been using this procedure for a decade or longer and the results have been very good. I will remove any leaves with obvious blight lesions as soon as possible and spray weekly and after every heavy rain. I have only lost a few tomatoes each year out of between 75 and 100 planted to Early Blight so until I find something that works better I will continue. I have noticed that the worst cases of EB tend to hit certain varieties harder than others and the worst infections usually happen early in the season when rains are more frequent.

Bill

[MrBig46]

Thanks for your comment. I've read it from you a few times, but I don't remember diluting the hypochlorite. Could you mention it here again. I'm thinking of spraying my black fabrics before the season for sure, which I use repeatedly.
Vladimír

[Tillerman]

Originally Posted by Milan HP

How far could parts of the infected plants get? Alternaria survives on those mainly in the ground. I'd say that the best bet could be on the other side of the house. Did you clean the contaminated area off the plant debris properly throughout the whole season? That is the key.
Milan HP


P.S. You might also consider applying calcium cyanamide (CaCN2) to treat the area where the infected plants used to be. It is said to kill some pathogens and pests. It's a good fertilizer too. Two weeks before you sow or plant anything there.

Thanks for the thoughts. I have a fair amount of area to relocate the plot, but the best area for optimal sun is probably 50+ feet away. I will look into calcium cyanamide.

[Tillerman]

Originally Posted by Milan HP

I still consider the wind blown debris of infected plants (dry leaves are brittle) that get onto the adjacent patches a potential hazard. Not a very serious one though, but I believe that it is better to be safe than sorry.

Milan HP


P.S. My nickname is Mr Caution.

Thanks

[Tillerman]

Originally Posted by MrBig46

Perhaps my compatriot and friend Milan HP will not be angry if I correct him a bit. Early blight is a leaf disease that overwinters on plant remains in the ground. If you have removed all the above-ground diseased parts of the plants, then the spores of Alternaria solani survive only in the remnants of the roots directly on the flowerbed where the plants were grown. So it is enough if you do not grow tomatoes in the same place, but it is possible to grow them right next door. Need not to put tomatoes somewhere on the other side of the garden, but the place of cultivation must be changed every year and on original infested flowerbed can be returned in three to four years.
Vladimír

Thank you. Even thought I have a little acreage, I'd like to use an adjacent area because of convenience and amount of light.

[Tillerman]

Originally Posted by PaulF

Many diseases including blights and wilts are soil borne and are transmitted by direct contact of leaves with soil. Water splashing on bare soil sends dirt onto leaves and the spores are in place. Any stressed plant is then more susceptible than a stronger plant. As tomatoes age over the growing season they weaken from reproduction and disease is more frequent. Certain varieties also are more susceptible than others.

An important safeguard to soil borne diseases like blights and wilts is a good mulching program. A barrier between soil and plant will go far in reducing disease. I use newspaper as a first layer and straw on top of that. After having tried several different combinations, for me this has reduced disease tremendously. My garden is so small it is impossible to rotate the crops enough that there is no overlap. I credit mulch with successful reduction in pathogen transmission...not elimination, but great reduction.

Thank you. This makes sense from my understanding of the mode of transmission. I haven't used a paper/plastic mulch for a few years; but, that may be the best preventive for a nearby plot.

[Tillerman]

Thanks for all replies, and as Winter progresses I will investigate all of the options. I seems to me that a major consideration is whether EB is soil-borne, air-borne, or both.